Plant and Soil

, Volume 73, Issue 1, pp 27–34 | Cite as

Influence of humic acid on iron required for the formation of hydroxyproline in discs ofBeta vulgaris L. storage tissue

  • D. Vaughan
  • B. G. Ord


When discs of beetroot storage tissue are washed (aged) in water for three days, there is at least a 100 per cent increase in the content of their cell-wall bound hydroxyproline. Humic acid, prepared from an agricultural soil, enhances this increase. The effects of humic acid on the increase in the hydroxyproline content of cell walls, as well as on the formation of14C-labelled hydroxyproline from14C-proline, are compared with those effects produced by the chelating agents 2,2′-dipyridyl and 8-hydroxyquinoline. It is suggested that humic acid enhances hydroxyproline formation either by a mechanism which renders more ferrous iron available for the hydroxylation of proline to hydroxyproline within the tissue, and/or a mechanism which stimulates the enzyme required for the hydroxylation process.

Key words

Beta vulgaris Cell walls Chelating agents Humic acid Hydroxyproline Iron Proline Proteins Storage tissue 


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  1. 1.
    DeKock P C 1960 The effects of natural and synthetic chelating substances on the mineral status of plants. Seventh Int. congr. Soil Science, Madison, Wisc., U.S.A. pp 573–579.Google Scholar
  2. 2.
    DeKock P C and Vaughan D 1975 Effects of some chelating and phenolic substances on the growth of excised pea root segments. Planta Berlin 126, 187–195.Google Scholar
  3. 3.
    Glentworth R and Muir J W 1963 The soil of the country round Aberdeen, Inverurie and Fraserburgh. Memoirs of the Soil Survey of Gt. Br. Scotland, Edinburgh. H.M.S.O.Google Scholar
  4. 4.
    Guminski S, Guminska Z and Sulej J 1965 Effects of humate agar-agar, and EDTA on the development of tomato seedlings in aerated and non-aerated water cultures. J. Exp. Bot. 16, 151–162.Google Scholar
  5. 5.
    Holleman J 1967 Direct incorporation of hydroxyproline into protein of sycamore cells incubated at growth inhibitory levels of hydroxyproline. Proc. Natn. Acad. Sci. U.S.A. 57, 50–54.Google Scholar
  6. 6.
    Hurych J and Chvapil M 1965 Influence of chelating agents on the biosynthesis of collagen. Biochem. Biophys. Acta. 97, 361–363.Google Scholar
  7. 7.
    Kivirikko K I and Leismaa M 1959 A colorimetric method for determination of hydroxyproline in tissue hydrolysates. Scand. J. Clin. Lab. Invest. 11, 128–133.Google Scholar
  8. 8.
    MacDonald I R, Bacon J S D, Vaughan D and Ellis R J 1966 The relation between ion absorption and protein synthesis in beet discs. J. Exp. Bot. 17, 822–837.Google Scholar
  9. 9.
    Searcy R L, Reardon J E and Foreman J A 1967 A new photometric method for serum urea nitrogen determination. Am. J. Technol. 33, 1–6.Google Scholar
  10. 10.
    Van der Werff M 1981 Ecotoxicity of heavy metals in aquatic and terrestrial higher plants. Ph.D. Thesis, Vrije Universiteit, Amsterdam. pp 77–104.Google Scholar
  11. 11.
    Vaughan D 1969 The stimulation of invertase development in aseptic storage tissue slices by humic acids. Soil Biol. Biochem. 1, 15–28.Google Scholar
  12. 12.
    Vaughan D 1974 A possible mechanism for humic acid action on cell elongation in root segments ofPisum sativum under aseptic conditions. Soil Biol. Biochem. 6, 241–247.Google Scholar
  13. 13.
    Vaughan D and MacDonald I R 1967 Invertase development in storage tissue discs ofBetavulgaris, its nature, extent and location. J. Exp. Bot. 18, 578–586.Google Scholar
  14. 14.
    Vaughan D and MacDonald I R 1971 Effects of humic acid on protein synthesis and ion uptake in beet discs. J. Exp. Bot. 22, 400–410.Google Scholar
  15. 15.
    Vaughan D and MacDonald I R 1976 Some effects of humic acid on cation uptake by parenchyma tissue. Soil Biol. Biochem. 8, 415–421.Google Scholar
  16. 16.
    Vaughan D, Cheshire M V and Mundie C M 1974 Uptake by beetroot tissue and biological activity of14C-labelled fractions of soil organic matter. Biochemical Soc. Trans. 2, 126–129.Google Scholar
  17. 17.
    Yip C C 1964 The hydroxylation of protein by horseradish peroxidase. Biochem. Biophys. Acta. 92, 395–397.Google Scholar

Copyright information

© Martinus Nijhoff/Dr W. Junk Publishers 1983

Authors and Affiliations

  • D. Vaughan
    • 1
  • B. G. Ord
    • 1
  1. 1.The Macaulay Institute for Soil ResearchAberdeenUK

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